Heat-activated enzyme helps break down corn more efficiently.

So far, the first generation of biofuels is being made from things like corn, palm oil, and sugar cane. But only a small part of these plants—a part we'd already been using for other things—is actually made into fuel. Being able to make biofuels from the rest of the plant would allow us to get more from existing crops, use the leftover biomass from food production, and allow us to process plants that grow on marginal terrain.

Unfortunately, most of the carbon in a plant is locked up in cellulose, a very tough polymer made from simple sugar molecules. Before we turn a plant into biofuel, we need to figure out how to break down the cellulose. Right now, that process takes harsh conditions and long treatments with enzymes, which significantly adds to the cost. But some bioengineers at a company in Massachusetts have made a plant that carries an enzyme that can help digest itself—but the enzyme remains inactive until the plant is processed.

Hemicellulose is a major component of plant cell walls. Its presence helps protect cellulose from digestion, so digesting it not only liberates sugar for making biofuels, but it also makes the sugar in cellulose easier to access. Digesting away hemicellulose is thus a key early step in biofuel production, and requires either harsh chemicals or expensive enzyme treatments.

The authors reasoned that placing the enzyme itself in the plants they were going to process would reduce the cost and complexity of digesting. But, when they placed the gene for one of those enzymes (a xylanase) into corn, its normal activity kicked in, and it started digesting the plant while it was still alive. The resulting plants were unhealthy, and the kernels of their corn were small and shriveled.

Since biofuel processing normally takes place at high temperatures, they decided to make the xylanase inactive by default, but allow it to be activated on demand. To engineer this version, they turned to a rather unusual form of molecular parasite called an "intein." These are short protein sequences that, when embedded inside a larger protein, splice themselves out, freeing themselves and leaving an intact protein behind. To get an intein that could be controlled, the authors identified one that was active in a species that is fond of high temperatures.

The team took the xylanase gene and inserted the sequence for the intein in the middle of it, which should inactivate the xylanase unless the intein splices itself out. After trying 23 different locations, they found a few where the resulting xylanase was inactive at low temperatures, but got activated as the temperature was raised (thus allowing the intein to remove itself from the resulting enzyme). They then did two rounds of random mutation and selection, screening for a greater difference before and after heat activation. The resulting xylanase had less than 10 percent of its normal activity before heating, but was more than 60 percent active after a two hour heat treatment.

When placed in plants, this didn't cause any of the adverse affects of the normal xylanase. And, more importantly, it made the plants easier to digest. After a two hour treatment at 75°C, yields of sugars from the plant matter were up by over 20 percent. In fact, the actual yield of glucose went up to 90 percent of maximum expected based on the weight of the plant mass. And all of that was obtained from the corn plant after the ears of corn were removed.

There are plenty of ways to potentially improve the intein construct. Additional enzymes can be added, and they can be targeted to tissues like the stalk or leaves, keeping them out of the edible part of the corn. But it's a good start towards bioengineering a plant that can help turn itself into useful biofuels.

It may sound cool but it also sounds like something like this can have all sorts of unintended side effects that may not be positive and possibly even disastrous. I'd never be on board with this simply because of a possibility it may damage or interfere with other biological material or wildlife.

Please stop even discussing this aberration, there is no such thing as "leftover biomass", crop residues MUST go back to the soil and form humus to sequester carbon and improve the soil by buffering the effects of drought or rain, and increase nutrient absorption, not increase carbon emissions by making and burning ethanol. Hell, these "leftovers" are even used as fodder for cattle in this terrible dry year for hay. Not sure that's the best fodder for them cows, but it's surely a much better usage than making ethanol.

Any such GMO project should be halted in its tracks immediately, this is really the worst thing you want to do when farming. Not even mentioning the economical aberration of using a food product such as corn to produce biofuel. Wasn't palm producing something like 10 or 20 times more biofuel than corn and algae 100 times more? Don't remember the data exactly, or where I read them, possibly in a TED Talk this year. OK, maybe corn would produce a couple more gallons of biofuel to the bushel if you add in the biofuel from cellulose, but it is still one of the most inefficient and most costly plants for producing ethanol. The only reason we do it is because of the usual corn production surplus. Not sure how that'd work this year with $8/bushel corn high price without extremely heavy subsidizing.

It may sound cool but it also sounds like something like this can have all sorts of unintended side effects that may not be positive and possibly even disastrous. I'd never be on board with this simply because of a possibility it may damage or interfere with other biological material or wildlife.

Ignorant much? It sounds like you haven't even bother to try to understand the precautions they used.

They inactivated the gene, and only high heat--way higher than a plant can survive--will activate it. Even if it somehow got out, it would *decrease* the fitness of the plants it got into. The ones that didn't pick it up would outgrow them, and none would end up carrying the gene.

I agree that testing and precautions are necessary, but they're addressing that. Come up with a real reason it would cause problems and you'll have a response worth reading.

Please stop even discussing this aberration, there is no such thing as "leftover biomass", crop residues MUST go back to the soil and form humus to sequester carbon and improve the soil by buffering the effects of drought or rain, and increase nutrient absorption, not increase carbon emissions by making and burning ethanol. Hell, these "leftovers" are even used as fodder for cattle in this terrible dry year for hay. Not sure that's the best fodder for them cows, but it's surely a much better usage than making ethanol.

Any such GMO project should be halted in its tracks immediately, this is really the worst thing you want to do when farming. Not even mentioning the economical aberration of using a food product such as corn to produce biofuel. Wasn't palm producing something like 10 or 20 times more biofuel than corn and algae 100 times more? Don't remember the data exactly, or where I read them, possibly in a TED Talk this year. OK, maybe corn would produce a couple more gallons of biofuel to the bushel if you add in the biofuel from cellulose, but it is still one of the most inefficient and most costly plants for producing ethanol. The only reason we do it is because of the usual corn production surplus. Not sure how that'd work this year with $8/bushel corn high price without extremely heavy subsidizing.

No kidding! Corn will always be more expensive/less efficient than other non-food crop alternatives. And other than petrol-based fertilizers, what will make up for crop residues in fertilizing the soil? Who outside of the oil and corn lobbies actually benefits from this?

Please stop even discussing this aberration, there is no such thing as "leftover biomass", crop residues MUST go back to the soil and form humus to sequester carbon and improve the soil by buffering the effects of drought or rain, and increase nutrient absorption, not increase carbon emissions by making and burning ethanol. Hell, these "leftovers" are even used as fodder for cattle in this terrible dry year for hay. Not sure that's the best fodder for them cows, but it's surely a much better usage than making ethanol.

Any such GMO project should be halted in its tracks immediately, this is really the worst thing you want to do when farming. Not even mentioning the economical aberration of using a food product such as corn to produce biofuel. Wasn't palm producing something like 10 or 20 times more biofuel than corn and algae 100 times more? Don't remember the data exactly, or where I read them, possibly in a TED Talk this year. OK, maybe corn would produce a couple more gallons of biofuel to the bushel if you add in the biofuel from cellulose, but it is still one of the most inefficient and most costly plants for producing ethanol. The only reason we do it is because of the usual corn production surplus. Not sure how that'd work this year with $8/bushel corn high price without extremely heavy subsidizing.

Plants absorb CO2 when they grow. Burning the corn would not increase carbon, but reduce it by the total amount of corn or ethanol in storage.

Your over-all post comes off a bit tinfoil hattish and exaggerated, but that does not detract from your good stuff: "OK, maybe corn would produce a couple more gallons of biofuel to the bushel if you add in the biofuel from cellulose, but it is still one of the most inefficient and most costly plants for producing ethanol. The only reason we do it is because of the usual corn production surplus. Not sure how that'd work this year with $8/bushel corn high price without extremely heavy subsidizing."

I wonder if this same process can be used for other plants. Grass maybe? If this can be proven safe - I'd love to be able to produce my own ethanol after mowing my lawn.

Sorry Chimel31, I'm going to pick on you...

Chimel31 wrote:

Please stop even discussing this aberration, there is no such thing as "leftover biomass", crop residues MUST go back to the soil and form humus to sequester carbon and improve the soil by buffering the effects of drought or rain, and increase nutrient absorption,

I think this is a wonderful point about the potential consequences of doing this (outside of the unknown GM risks). Obviously this process wont be 100% efficient, however. I wonder what the biproduct is of this kind of treatment. Is it hazardous, or can it be used for exactly the same purposes you describe? I'd assume the former, but I'd love to get confirmation on this one way or the other.

Chimel31 wrote:

not increase carbon emissions by making and burning ethanol.

Ethanol has a lot of upsides as well, especially compared to gasoline.

I'm sorry - I think ethanol is here to stay. Which would mean the real question would be, how can we make it the most efficiently.

Chimel31 wrote:

Hell, these "leftovers" are even used as fodder for cattle in this terrible dry year for hay. Not sure that's the best fodder for them cows, but it's surely a much better usage than making ethanol.

The farming industry is usually very efficient, finding uses for what would essentially be waste. However, I would find it hard to argue that a replacement for hay is better use than a more efficient biofuel extraction process.

Chimel31 wrote:

Any such GMO project should be halted in its tracks immediately, this is really the worst thing you want to do when farming. Not even mentioning the economical aberration of using a food product such as corn to produce biofuel.

Aren't you really missing the point here? We already make biofuel from corn. This whole article is essentially about extracting the ethanol from parts of the plant you can't eat. As far as I can tell, this could eventually mean one of two things:1) Eat the corn, get fuel from the rest2) Get more fuel from less plants which allows more corn to eat.

Chimel31 wrote:

Wasn't palm producing something like 10 or 20 times more biofuel than corn and algae 100 times more? Don't remember the data exactly, or where I read them, possibly in a TED Talk this year. OK, maybe corn would produce a couple more gallons of biofuel to the bushel if you add in the biofuel from cellulose, but it is still one of the most inefficient and most costly plants for producing ethanol. The only reason we do it is because of the usual corn production surplus. Not sure how that'd work this year with $8/bushel corn high price without extremely heavy subsidizing.

Burning the corn would not increase carbon, but reduce it by the total amount of corn or ethanol in storage.

Burning the extra ethanol produced from cellulose will release more CO2 in the atmosphere, compared to disking and mulching or plowing the same crop residue on the field. The carbon from cellulose gets converted to humus, whose worth is like platinum when you are farming (manure being gold. ;) Edit: Water, diamond; draining and irrigation, kryptonite; Sun, damn it!; ...

hobbsb wrote:

I wonder what the biproduct is of this kind of treatment. Is it hazardous, or can it be used for exactly the same purposes you describe?

The technology and byproducts seem innocuous enough, probably much more so than ethanol from grain, which is also very costly because you need first to convert starch into sugars, so it's appealing. It's just that once the crop residues go out of the farm to the processing plant at some fuel cost in transportation and a lot of extra work and more processing fuel, they are not likely to come back as fertilizer, which would double the fuel cost of transportation, and actually triple it (or something of that order) when you add the cost of spreading the fertilizer on the field instead of leaving it on site in the first place. No farmer in their right mind would go for it, since most corn is grown no-till, which means you remove all unnecessary heavy machinery steps that increase soil compaction, not even mentioning the extra work and time cost of transporting and processing the residue. It does not even make a bit of common sense to transport the residue back and forth anyway.

As for the content of the byproduct, it is similar to what happens to the manure processed in a gas digester to extract biomethane, you would probably lose some of the nutrients and certainly a lot of the humus-building properties of this crop residue if you remove the energy-rich carbon from it (2 atoms of carbon for each molecule of ethanol.) With the triple cost of transportation, I am sure the balance is still positive, but it still looks like a lot of energy might be wasted.

And before anybody asks, no, the transportation cost is not free, since current ethanol corn is made from grain, so the crop residue cannot be transported alongside with the grain for free. The volume of this crop residue would be much bulkier and most likely heavier than the grain, for what I assume a lower yield of the already low yield of biofuel from corn grain, so maybe it would need extra processing such as crushing or drying before being transported. A possible solution to some of these problems could be to create local automated processing plants on each farm, but this is a pioneer technology, so we're still decades away from such a stage. So the best automated processing plant will still be the field for a long while.

hobbsb wrote:

Ethanol has a lot of upsides as well, especially compared to gasoline

Ethanol from corn grain is a whole other debate, I am mostly answering the article about making ethanol from the corn crop residue, as it seems the article shows only the ideal side of the process, without any consideration for cost and environment. If the corn fields become less fertile because of the loss of humus and if the soil is heavily subject to erosion because of the lack of mulch cover and humus, is it really worth in the long term squeezing a few extra drops of ethanol from the cellulose? There is absolutely no information on the yield of ethanol per tonne in this article, or about the energy requirements and efficiency of the process, so it's hard to evaluate anything. Ethanol does make gas less polluting, but there are several and better ways to produce it.

hobbsb wrote:

Aren't you really missing the point here? We already make biofuel from corn

As I said, I won't enter the debate on ethanol made from corn grain in these comments (although I'm rather hot on it! ;), I will only mention that this ethanol making is heavily subsidized, so without doing anything, you're already paying 40-50 cents per gallon of ethanol right out of your tax dollars since the late 70s' first ethanol subsidy (30+ billion dollars since G.W. Bush's 2004 new subsidy law.) I assume ethanol from corn cellulose would benefit from the same or an equivalent subsidy. However, these scientists got their funding for this cellulose project, so of course they will try to push it as much as they can, and I applaud and fully support any attempt at increasing our energy sustainability and independence. It's just that at some stage, we must look beyond the process, at the whole eco and econosystem (isn't English a great language? ;) and decide if it makes sense. I'll be the first to admit that it's probably too early to make this decision and more research exploring the cellulose track is still necessary. I am not even mentioning the damages (not just risks) to biodiversity inherent to GMOs, since most Mexican creole (i.e. indigenous) corn varieties are already contaminated by Monsanto genes even though GMOs are not authorized in Mexico (or were not until recently, not sure what the current status is.) Oh wait, I just did mention these damages! ;)

Interesting ethanol production comparison of different crops at 9:30, but this is not the talk I was thinking about (and I watched all 1000+ of them, ain't I clever? ;) Here's the one I had in mind, with a similar graph at 1:30 showing micro-algae yielding probably something like 25 times more gallons of biofuel per acre than corn. This is also years away from industrialized production stage, with its own issues no doubt, such as water and space requirements.http://www.ted.com/talks/jonathan_trent ... _pods.html

The whole idea of biofuels is both idiotic and wicked. Its wicked because it is subsidized conversion of food to gasoline, thus raising the price of food and increasing hunger for the poorest of the world. Its idiotic it can have absolutely no effect on the supposed problem it is being done to address.

You simply cannot convert enough corn, even including the residues, to make a large enough difference to CO2 emissions to have any effect on Global Warming. Read the IPCC reports, figure out how big reductions are required, then ask how much of a reduction can you reasonably expect from biofuels.

And that is another reason why its even more wicked. It is doing something which is totally ineffective as a solution to the supposed problem, whose ONLY effect is to raise food prices for the poor.

If I could just reiterate what Chimel31 is saying, he/she makes a really good point. Agriculture places a lot of importance in crop residues to boost soil fertility these days in preference to artificial fertilisers (which require an enormous amount of natural gas to produce). Harvesting residues is a big step backwards to some of our worse agricultural practices.

So far, the first generation of biofuels is being made from things like corn, palm oil, and sugar cane. But only a small part of these plants—a part we'd already been using for other things—is actually made into fuel. Being able to make biofuels from the rest of the plant would allow us to get more from existing crops, use the leftover biomass from food production, and allow us to process plants that grow on marginal terrain.

In the case of corn, half the plant is havested for grain. The majority of the rest needs to stay in the fields. And since corn ethanol by-products are usable to supply food, they have no net negative impact on current food supply. That can't be said of fuel specific crops. There is no such thing as maginal terrain for fuel. It can either grow a food crop or it can't grow anything.

Quote:

there is no such thing as "leftover biomass" crop residues MUST go back to the soil and form humus to sequester carbon and improve the soil by buffering the effects of drought or rain, and increase nutrient absorption

Quoted because it can't be said too many times.

Quote:

Not sure how that'd work this year with $8/bushel corn high price without extremely heavy subsidizing.

What subsidizing are you claiming? Corn ethanol isn't subsidized.

BTW, it seems to be working ok where there is corn. The corn is being turned into a protein rich food, supplementing the shortage of soybeans. It is also working due to high gas prices, which it reduces the cost of.

Quote:

Corn will always be more expensive/less efficient than other non-food crop alternatives.

And other than petrol-based fertilizers, what will make up for crop residues in fertilizing the soil?

Much of the minerals removed should still be effective if returned to the soil. Any loss of nitrogen could be replaced without using hydrocarbons.

Quote:

I wonder what the biproduct is of this kind of treatment. Is it hazardous, or can it be used for exactly the same purposes you describe?

After the cellulose is broken down, it can no longer be used to help soil buffer heavy rain or drought.

Quote:

As far as I can tell, this could eventually mean one of two things:1) Eat the corn, get fuel from the rest2) Get more fuel from less plants which allows more corn to eat.

If we deplete the soil by removing too much biomass. We get less of everything. In our current method of food production. Corn ethanol has no net impact. It simply becomes a substitute for soybeans.

Quote:

I think it's terribly stupid to turn corn into ethanol

I don't think, I know it's stupid to post in ignorance.

Quote:

I will only mention that this ethanol making is heavily subsidized, so without doing anything, you're already paying 40-50 cents per gallon of ethanol right out of your tax dollars since the late 70s' first ethanol subsidy (30+ billion dollars since G.W. Bush's 2004 new subsidy law.) I assume ethanol from corn cellulose would benefit from the same or an equivalent subsidy.

WRONG!

Corn ethanol is NOT subsidized! And you assume wrong. Cellulose is subsidized at $1 per gallon!

Quote:

Its wicked because it is subsidized conversion of food to gasoline, thus raising the price of food and increasing hunger for the poorest of the world.

Wrong. Wrong. Wrong. It's not subsidized. It has no negative impact of food. The DDG after processing makes a cheap feed often sent to third world countries.

Its wicked because it is subsidized conversion of food to gasoline, thus raising the price of food and increasing hunger for the poorest of the world.

Wrong. Wrong. Wrong. It's not subsidized. It has no negative impact of food. The DDG after processing makes a cheap feed often sent to third world countries.

Regardless of the issue of subsidies (corn in the US most certainly is subsidised, and corn ethanol has been incentivised by the US ethanol mandate), I'm not sure how you can claim that ethanol has no impact on food prices when simple supply and demand dictates that it does. If you increase demand by opening corn and other grains up to an entirely new industry, of course prices are going to go up. But don't take my word for it, the World Bank concluded that between 2002 and 2008, biofuels were responsible for 70-75% of grain price rises during this period (at the end of which you may recall were food riots in several countries).

Holy shit, this is an awesome, ingenious use of intein chemistry! I love it!

Yeah, modern era human history is full of ingenious uses of chemistry; DDT, sarin...all kinds of great stuff!

Quote:

I think it's terribly stupid to turn corn into ethanol (though, if you are going to do it anyway, I'd rather it be done slightly more efficiently).

If you're increasing the efficiency of a bad habit, you're adding more incentive to continuing the use of said bad habit; ie; a BAD thing. Prime example of when (purportedly) good intentions have the exact opposite effect.

Since there's still mass starvation in many parts of this globe, the last thing we should ever do is use food to manufacture vehicle fuel.

This is wrong on so many levels, environmental and health hazard.For all those people trying to put a positive pro spin on this, have an invested interest or just enjoy discussion competitions.We may not experience the side effects now,,, future generations...

Exactly so. It may be sensible to reduce CO2 emissions. It may even be sensible to try to reduce them from the use of oil for transport, though that's a large step and needs quantitative justification. I don't personally think its the easiest or most important target, but suppose you do. The point is still that biofuels will do neither on the scale required to have any effect on Global Warming, and that attempting either to reduce CO2 emissions or oil consumption for transport by using them will produce global hunger.

The only people who will benefit will be the corn lobby.

This is not the first time. Consider the move to polyunsaturated fats, which basically meant corn oil. Consider the move from cane sugar to fructose, which basically meant corn syrup. Corn oil in the diet solved a non-existent saturated fats problem, and has had disastrous side effects. The effects of fructose, one ingredient of the low saturated fat drive, has had even worse ones.

For some reason, the green lobby never seems to look critically at the motives and the tradeoffs of any group which promotes their product as a green solution. But often the side effects are worse than what they are replacing, and the motives just as venal.

Quote:

Regardless of the issue of subsidies (corn in the US most certainly is subsidised, and corn ethanol has been incentivised by the US ethanol mandate), I'm not sure how you can claim that ethanol has no impact on food prices when simple supply and demand dictates that it does. If you increase demand by opening corn and other grains up to an entirely new industry, of course prices are going to go up. But don't take my word for it, the World Bank concluded that between 2002 and 2008, biofuels were responsible for 70-75% of grain price rises during this period (at the end of which you may recall were food riots in several countries).

I don't understand how people are turning this into a "Bioengineering bad" argument. Bioengineering, or even more selective breeding has proven throughout history that it can produce crops with higher yield under harsher conditions. There are still a lot of people in this world starving right now that could absolutely benefit from expanded bioengineering efforts, but people that are in a position to be picky with their foods are right there fighting it every step of the way. As long as its properly tested and regulated, it is one of the few things that really can solve world hunger.

As far as this yielding less food overall... if they have higher yields, and can "process plants that grow on marginal terrain." they're probably expecting this as an offset. That being said, I do recall as another poster mentioned, things like algae can have higher yield in terms of bio-fuel, and I have heard this from several talks as well.

For the people that feel this will stop CO2 emission, bio-fuel does often have "reduced" carbon, but even it releases some.

So... Genetically engineered corn. My question is, how does that enzyme affect the waste left over after the rest is made into fuel? And how will it affect everything else in the ground?

The bigger question is that while they took painstaking effort to change the genome of everything but the ears of corn, is there any gene spillage over into the part that we eat? If so are there any negative side effects to the plant? To the way it will be digested?

So... Genetically engineered corn. My question is, how does that enzyme affect the waste left over after the rest is made into fuel? And how will it affect everything else in the ground?

The bigger question is that while they took painstaking effort to change the genome of everything but the ears of corn, is there any gene spillage over into the part that we eat? If so are there any negative side effects to the plant? To the way it will be digested?

They haven't taken the effort to keep the ears of corn from being changed. The ears of corn were removed so they could see the production increase of the plant minus the part that would be sold for food. Note that the plants were still unhealthy appearing compared to unmodified plants, just significantly less effected by the change than their first try, (i.e. over 90% better than their initial shriveled thing).

I would also think that the remaining post-process waste may have some useful minerals such, but overall we’re going to need to mine a lot more Potash for these farms.

Corn as a fuel-stock crop is, well, dumb. I'm not even talking about the "plundering the pantry to fill the gas tank" argument here.

If they're finding ways to efficiently process hemicellulose, that needs to be attached to switchgrass, or other non-traditional 'crops' that can grow on land unsuitable for normal cultivation. A perennial grass is great for a whole lot of reasons: plant once/mow forever, drought tolerant, anchors topsoil, provides cover/food for lots of wildlife, oh, and requires no chemical fertilizer.

If we could make something like that happen, I'd be very happy. This article outlines a solid step in that direction, but the focus has to move away from corn, which is a pretty greedy and needy plant in its current form.

Very cool use of temperature dependent intein splicing to control activation of an enzyme. I'm impressed.

Anyone have ideas on the structure-function relationship of the intein that can make it temperature activated? The mechanism of splicing is the same for all inteins. So maybe the length of the intein or formation of tertiary structures that denature at high temperatures could be important.

For the economic arguments for or against this, clearly use of this technique in switchgrass is better. The biochemistry is the same in switchgrass and corn, so it doesn't really matter what organism they demonstrate the technique in to begin with.

If allowed to spread in the wild the genes would quickly be selected against. Caution is good, but I don't see the danger for this gene. If you're going to be worried about GMO corn, Bt-corn is a more appropriate target since it increases the fitness of the host organism.

People can be pretty ignorant of how much genetic manipulation nature does. There are trillions of bacteria on/in your body constantly mutating and producing genes of new potentially dangerous functions. I think that's a bit more to be worried about than a heat activated gene that breaks down hemi-cellulose in corn.

I can't wait for this stuff to blow into someone's heirloom/organic cornfield. Maybe Monsanto will buy another judge to order their crop burned again.

Yeah, I was devastated for this poor farmer. 20 or 40 years (I don't remember exactly which) of selecting organic corn adapted to the local soil and climate (he was a breeder, not just a farmer) just went up in flames and ashes because neighboring GMO fields contaminated his. There was not high enough a price to put on his life work for the good of farmers, and that despicable judge should have lighted that fire from closer. Much closer...

randomletters1 wrote:

If they're finding ways to efficiently process hemicellulose, that needs to be attached to switchgrass, or other non-traditional 'crops' that can grow on land unsuitable for normal cultivation.

+1, that's the second thing that came to my mind (after I got over the outrage of removing the crop residue from the fields! ;) I don't know what to make of this article. On one hand, it's great to summarize the pay-for-content papers most of us can't access, but on the other hand, I would expect from Ars Technica a far more critical (not just negative) and broader view of the story. Maybe it should be made clear at the beginning of each article if it's just communicating about a new paper with no comments, or if it's an in-depth analysis of the paper, its consequences, integration in real life, economical and environmental concerns, is it pure research or is there a plan to deploy the technology, etc.

Miles wrote:

Quote:

So far, the first generation of biofuels is being made from things like corn, palm oil, and sugar cane.

Thanks for reminding me of the very first sentence of the article. I can't believe I overlooked how (OK, relatively) wrong it was. It should be "the first generation of bioethanol," not "biofuels," or soybeans should have been added to the list of crops since biodiesel (a biofuel) is almost exclusively made from soybean oil.

Miles wrote:

What subsidizing are you claiming? Corn ethanol isn't subsidized.

WRONG!Corn ethanol is NOT subsidized! And you assume wrong. Cellulose is subsidized at $1 per gallon!

Wrong. Wrong. Wrong. It's not subsidized. It has no negative impact of food. The DDG after processing makes a cheap feed often sent to third world countries.

Corn ethanol has been subsidized continuously since 1978. The subsidy varied a few times but has always been between 40 to 50 cents per gallon of ethanol. G.W. Bush renewed the subsidy in 2004 (took effect in 2005) to the amount of 45 cents per gallon (against the 51 cents he and the lobbies first asked) and it is still in effect today. The only change G.W. Bush made was that now, the subsidy goes to the "blenders" (i.e. the oil companies) instead of the farmers. No surprise there...

Miles wrote:

The corn is being turned into a protein rich food, supplementing the shortage of soybeans. It is also working due to high gas prices, which it reduces the cost of.

Today, corn is grown most exclusively for starch, which is the source of most industrial processes in corn processing plants, and contains about 4% protein. Low-protein corn in the 50s contained about 7-9% protein, high-protein corn 9-14% (the same corn varieties, but with 3.5 more nitrogen than the nitrogen-deficient low-protein corn.)

Corn can in no way supplement soybeans, whose protein content is 40% of the whole grain (which also contains 20% of oil). It is the other way round, and if there is a shortage in the U.S., soybeans can be imported from Brazil and Argentina at roughly the same cost as local soybeans, since prices of this commodity are global.

In addition, animal feed is made from soybean meal, which is the byproduct of the extraction of soybean oil by solvents and is thus far more concentrated in proteins than the raw grain, at about 48%. You can get similar ratios with corn, about 40% for corn gluten feed (more fiber) and even 60% for the highly concentrated corn gluten meal, but these are the byproducts of industrial corn processing (you know, after soaking corn in sulfuric acid and the like) and still use only about 10% of the whole grain.

I don't think you mean "food" as in human food, but "feed" as in animal feed. Corn is present in many food and industrial sectors only because it is so cheap and so productive, yielding 300 bushels an acre compared to 70 for soybeans (both in good conditions). Many dryland farmers didn't even reach 10 bu/a this year and had to chop it green for fodder, so forget about corn complementing the protein content of feed.

As far as proteins in feed are concerned, corn comes far behind soybean (63% of feed proteins,) canola (12%), cottonseed (8%), sunflower (6%), fish meal (4%) and peanut meal (4%). These data are just over 10 years old and probably haven't changed that much today.

Compared to soybean, corn contains almost no tryptophan and very little lysine, which are two essential amino acids for humans. And the same goes for several other standard amino acids, since soybean has an almost complete range of them.

I guess this enzyme helps composting this stuff? Composting already creates heat, methane & fertilizer. But, it takes time to process. Is this enzyme processing the stuff in a matter of hours instead of days?